In fact, it's not even an area inside the home, says real estate mogul Sean Conlon: "The most important bit is your landscaping in the front, because your street presence is absolutely the most important. It's called curb appeal."

After all, it's the first thing people see, and first impressions matter, says Conlon, who hosts CNBC's "The Deed: Chicago": "You want your house to look beautiful from the outside."

He continues: "Your lawn should look beautiful. Your shrubs should be nice and colorful and well taken care of. ... Your shutters and windows should look nice.

"When people pull up, they should go, 'I could picture myself pulling up in the evening and this being my home. That's what curb appeal is."

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Sean Conlon of "The Deed"

Curb appeal is the reason Conlon says it's OK to spend five figures on a custom door: "When you are renovating a house you want to find ways to make it stand out from all the other homes on the market and what better way than having the most beautiful entrance on the block? Buyers lap that stuff up."

Fellow real estate mogul and host of "The Deed," Sidney Torres, agrees on the importance of investing in curb appeal.

"You want the front of the house to look amazing when people drive by," Torres tells CNBC, because at the end of the day, "you want them to want to come inside the house."